On my commuter I have a ton of lights because the drivers in New England plus the darkness with few streetlights means I am not visible otherwise. I bought a headlight/taillight pair from Target for $12, used taillight from my LBS for $3, front and back blinkers for $10, plus a modified headlamp from the Ocean State for like, $5. All included batteries. I spent about $20 for high vis lights. My commuter is intentionally fred-ly, so I don't care about the appearance/weight.